How to get itin number for nonresidents?

There are only 3 types of nonresident who can get an ITIN:

• Nonresident alien who is required to file a U.S. tax return
• Nonresident alien claiming a tax treaty benefit
• Nonresident alien student, professor or researcher filing a U.S. tax return or claiming an exception

Also, ITIN number is available for nonresidents who do not have an SSN or are not eligible to get one and are required to furnish a federal tax identification number or file a federal tax return.